Spinning towards robust microwave generation on the nano scale

Spin-torque oscillators (STOs) are nanoscale devices that generate microwaves using changes in magnetic field direction, but those produced by any individual device are too weak for practical applications. Physicists have ...

Light may magnetise non-magnetic metals, propose physicists

Physicists from Nanyang Technological University, Singapore (NTU Singapore) and the Niels Bohr Institute in Copenhagen, Denmark, have devised a method to turn a non-magnetic metal into a magnet using laser light.

Alternating currents cause Jupiter's aurora

An international team of researchers has succeeded in measuring the current system responsible for Jupiter's aurora. Using data transmitted to Earth by NASA's Juno spacecraft, they showed that the direct currents were much ...

Will your future computer be made using bacteria?

In order to create new and more efficient computers, medical devices, and other advanced technologies, researchers are turning to nanomaterials: materials manipulated on the scale of atoms or molecules that exhibit unique ...

Proteins trapped in glass could yield new medicinal advances

Researchers at Chalmers University of Technology, Sweden, have developed a unique method for studying proteins which could open new doors for medicinal research. Through capturing proteins in a nano-capsule made of glass, ...

A peculiar ground-state phase for 2-D superconductors

The application of large enough magnetic fields results in the disruption of superconducting states in materials, even at drastically low temperature, thereby changing them directly into insulators—or so was traditionally ...

Approaching the magnetic singularity

In many materials, electrical resistance and voltage change in the presence of a magnetic field, usually varying smoothly as the magnetic field rotates. This simple magnetic response underlies many applications including ...

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Electric field

In physics, the space surrounding an electric charge or in the presence of a time-varying magnetic field has a property called an electric field. This electric field exerts a force on other electrically charged objects. The concept of an electric field was introduced by Michael Faraday.

The electric field is a vector field with SI units of newtons per coulomb (N C−1) or, equivalently, volts per metre (V m−1). The SI base units of the electric field are kg·m·s−3·A−1. The strength of the field at a given point is defined as the force that would be exerted on a positive test charge of +1 coulomb placed at that point; the direction of the field is given by the direction of that force. Electric fields contain electrical energy with energy density proportional to the square of the field intensity. The electric field is to charge as gravitational acceleration is to mass and force density is to volume.

A moving charge has not just an electric field but also a magnetic field, and in general the electric and magnetic fields are not completely separate phenomena; what one observer perceives as an electric field, another observer in a different frame of reference perceives as a mixture of electric and magnetic fields. For this reason, one speaks of "electromagnetism" or "electromagnetic fields." In quantum mechanics, disturbances in the electromagnetic fields are called photons, and the energy of photons is quantized.

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